LA block running magnum heads

I built my first 360 that way, you can check out by build thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=166285

Judging by what you've said so far I think it would be a worthwhile swap. However there is an option you may want to look into and that is getting a set of RHS LA-X heads; these have the closed chambers and the ports are similar to the Magnums but improved significantly. They also allow you to run LA-style shaft-mount rockers which are arguably a better design for higher HP levels, and the best part have the LA-style intake bolt pattern which gives you WAY more options for intake manifolds.

You can find Magnums for cheap at most junkyards but 80% of the time they have cracks between the valve seats which makes them useless. Also they can't support cams with over .525" lift without having the guides cut down.

If you haven't bought a core engine yet I'd suggest getting an entire Magnum engine since it will have provisions for a roller cam from the factory. But overall you can run any LA cam out there, there are literally hundreds of choices from Comp, Lunati, Hughes, and many others.

What kind of car is it going in? And the intended use?